Dr. Stephen Strange paced the room, deep in thought. Wong sat across from him, engrossed in a book detailing ancient magical techniques. The air was thick with an unspoken challenge, one that would soon erupt into an unexpected duel.

"Wong, I propose a duel," Dr. Strange declared, a mischievous glint in his eye. "A duel of... flatulence," he added, his tone both serious and playful. Wong looked up, a smirk spreading across his face as he set his book aside.

"You underestimate me, Strange," Wong replied, standing up and stretching as if preparing for a great battle. Dr. Strange chuckled, taking a stance beside him. The duel commenced, each of them summoning their inner powers to produce the most impressive, if comical, sounds.

The duel continued with both Dr. Strange and Wong exchanging playful jabs and laughing heartily at each other's attempts. "I must admit, Wong, you have a certain... finesse," Strange joked between bouts of laughter.

"Perhaps next time, a more traditional duel," Wong suggested, still chuckling. Dr. Strange nodded, a grin on his face. The two of them resumed their positions, content in the knowledge that their friendship was stronger than any spell or duel.

Dr. Strange returned to his pondering, while Wong picked up his book, the bond between them reaffirmed by their shared humor. The Sanctum, ever a place of mystery and magic, now held yet another tale within its ancient walls.